Cannabinoid receptor 1 (CB1R) regulates neurite outgrowth, has important functions in central nervous system development, and is a drug target for several diseases. Bromberg et al. used a combination of transcriptional profiling on DNA arrays with graph theory analysis of known signaling networks to explore the effects of signaling by the CB1R. Unexpectedly, the analysis predicted that the product of the breast cancer susceptibility gene BRCA1 was likely to regulate transcription factors activated during CB1R-stimulated neurite outgrowth. Furthermore, depletion of BRCA1 did indeed inhibit CB1R-stimulated neurite outgrowth. The transcription factor PAX6 was also regulated in response to cannabinoid signaling. This type of network analysis is useful to define the logic of complex signaling decision processes.